This invention relates to a polypeptide found in the venom of the Agelenopsis aperta spider and to a polypeptide having substantially the same amino acid sequence and substantially the same activity as said polypeptide. The polypeptides and the pharmaceutically acceptable salts thereof block calcium channels in cells including neuronal and muscle cells of various organisms including invertebrates and vertebrates. This invention also relates to the use of said polypeptides and their salts in blocking calcium channels in cells such as cells in the nervous and muscular system of an organism, per se, and in the treatment of calcium channel mediated diseases and conditions in a mammal. Further, this invention relates to compositions comprising said polypeptides and salts thereof.
Compounds which are calcium antagonists have a variety of utilities. Calcium antagonists can find clinical application in the treatment of such conditions as angina, hypertension, cardiomyopathies, supraventricular arrhythmias, aesophogeal achalasia, premature labor and Raynaud's disease among others. See W. G. Nayler, Calcium Antagonists, Academic Press, Harcourt Brace Jovanovich Publishers, New York, N.Y. 1988, the teachings of which are incorporated herein by reference. Further, such compounds are useful in the study of the physiology of cells such as neuronal and muscle cells.
Other polypeptides isolated from Agelenopsis aperta are disclosed in U.S. Pat. No. 5,122,596.